In the prior art, electrical plug connector devices may fundamentally be designed as a socket or as a plug and they usually have a contact insert block, in which the generic elongated contact elements that are inserted are designed as elongated contact pins in the case of a plug as an electrical plug connector device and are designed as a socket in the case of an electrical plug connector device, the generic contact elements are embodied as elongated contact sockets. Such electrical plug connector devices are described in the standards DIN VDE 0623, IEC 60309-1, -2 and EN 60309-1, -2 in particular.
The contact elements that are used serve accordingly for the corresponding mechanical and electrical coupling to a mating contact element of a complementary design. An elongated contact pin is thus mechanically and electrically coupled to an elongated contact socket, i.e., the contact socket receives the contact pin in its interior and/or the contact pin receives the contact socket over its entire external extent. The sections of a contact element that serve the purpose of coupling and/or receiving a mating contact element are also referred to below and in the claims as the receiving section.
Furthermore, such a contact element will usually have a section adjacent to the receiving section or at a distance therefrom, to serve the purpose of mechanical and electrical coupling and/or to receive an electrical connecting conductor.
The generic elongated contact elements thus consist essentially of electrically conductive material, traditionally a metal.
EP 1 783 868 relates to one such contact element, designed as an elongated contact pin, which is molded from a flat solid material by blanking and bending and has an essentially hollow cylindrical cross section along its receiving section. The contact pin described there conforms to the description in the specifications DIN VDE 0623, EN 60309-2, and it saves on material in comparison with hollow cylindrical contact pins manufactured from solid material by cutting or abrasive removal of material and in comparison with contact pins of solid material, i.e., without a hollow cylindrical cross section. However, according to EP 1 783 868, edges that must be joined by intermeshing teeth abut against one another because of the contact pin being bent from blanked flat material with mushroom-molded extensions formed on one edge to engage with complementary recesses in the other abutting edge, so unwanted contaminants and/or moisture can penetrate into the edge interspaces.
It has been found in particular that contaminants and/or moisture penetrating into such edge interspaces and possibly remaining there can lead to unwanted oxidation and/or corrosion, which may in turn result in increased transfer resistances in power transmission.